Modern elevator installations generally try to guarantee reliable operation even in the event of fire. On the one hand, the evacuation of persons and/or vulnerable material from the stories affected by the fire should generally be guaranteed, and on the other hand, a functionally capable elevator should be available for the transport of fire service personnel and their extinguishing material. In either case the use of extinguishing water should not have the consequence that the elevator installation or the fire service elevator no longer functions. This applies not only to the use of a sprinkler installation on a story, but also to the use of extinguishing water by the fire service.
This generally means that electrical components of the elevator installation should remain dry. In addition, it generally means that a support means on a drive pulley is still driven as desired. Extinguishing water can in that case have a negative influence on the traction of the support means on the drive pulley. On the one hand extinguishing water can directly reduce the coefficients of friction between the drive pulley and the support means and on the other hand lubricant present in the extinguishing water can additionally negatively influence the traction between support means and drive pulley. A support means wetted by extinguishing water can thus lead to reduction in traction or even to complete loss of traction. In the case of, in particular, a substantial difference between the weight of the elevator cage and of a counterweight an uncontrolled travel of the elevator cage can then arise, which has to be stopped by safety brakes. Faultless functioning of the safety brake or the braking retardation of the brake shoes thereof on guide rails can, however, also not be guaranteed if the brake shoes of the guide rails are moistened by extinguishing water.
The use of belt-like support means instead of steel cables can have the problem of a heightened loss of traction between support means and drive pulley. The synthetic material surfaces of belt-like drive means change their traction properties in the case of wetting by extinguishing water more strongly than steel-cable-like support means. This can make it necessary to conduct away or collect the extinguishing water in controlled manner. It can be necessary to prevent support means sections which co-operate with the drive pulley from being wetted by extinguishing water.
The extinguishing water normally penetrates into the elevator shaft by way of the shaft doors of the elevator shaft. In that case the extinguishing water flows on a story floor under the shaft doors through into the elevator shaft. International published specification WO 98/22381 A1 discloses an elevator installation with a drainage system at the shaft doors as well as mechanically positively inter-engaging flow barriers at each shaft door. It is attempted in this manner to keep the elevator shaft at the outset free of extinguishing water over its entire height. However, a possible disadvantage of this solution can be that each story has to be equipped, with a high cost outlay, with appropriate drainage pipes and the said flow barriers.